Inverter????

[Rincon Schooner]

We love our 2004 GS 8379 Atrium ….. I’ve made numerous repairs on our “old” rig and I have conquered most systems. Could it be that my rig DOES NOT have an inverter??? If it does, could it be “turned off”??? We “boondock” camp at the beach twice a month (two nights at a time)…..and, the house batteries provide lighting at night. If we run the microwave or the house batteries drop a bit from showing a “full charge”, I run the generator for a few minutes. If we watch TV, I have that plugged into a small lithium battery that provides power for 6 hours or more, and my signal comes from my I-phone and through an HDMI cable to the TV. My buddy says there is definitely an inverter…. I’ve been unable to find it…. I always assumed 110v outlets in the coach can only function if you are connected to shore power, or, when the generator runs. Do some Gulfstreams come without inverters?… Or could mine be shut off?…. Any assistance will be greatly appreciated!!!!!…. Rob

[Bike Dr]

You should have a control panel for it somewhere! i have an 05 Atrium and mine is located in the front left cabinet above the drivers seat. it will have buttons on it that should show charge, invert ,shared power and setup. the charger may also be the inverter as mine is! my inverter is located in an outside compartment where the shore power connects behind the rear driver side axle. when you plug the coach in you should hear it begin to hum or buzz..

[Chuck v]

Schooner,


The gas coaches likely have only two battery banks -- one for engine starting/vehicle lights and another one for 'house' loads like interior lights and accessories. In that case the inverter may be built into the house battery charger (12 volt converter) so look for its location to be near the house battery bank.


My diesel pusher coach had a third battery bank dedicated to the inverter and for starting the large diesel generator. This bank was up under the windshield (above and in front of the generator...) and the inverter itself was in the front bay on the driver's side.


Wherever your inverter is located, it will be very near a battery bank, as they pull quite a large 12 volt load current when operating at rated capacity. My 2500 watt inverter could pull at least 200 amps... A 1500 watt inverter would max out at about 125 amps and for a typical load (residential refrigerator) could average 50 amps of 12 volt input when the frig is running... Cables from the bank will be heavy -- at least 4 or 2 gauge or larger. Mine were 00 gauge size which is a wire diameter of 0.3648 inches...and with insulation makes these about the size of a small garden hose. You should have no issues finding the cables to your inverter if they exist.



Chuck

[Rincon Schooner]

Thanks Chuck… if I had an inverter, the outlet plugs should provide 110v power when boondocking, right?… unfortunately, they don’t, soooo, is it turned off?

[Bike Dr]

It could be turned off in the breaker panel, it also has a reset on the back of the unit it's self, and I can turn off mine on a remote panel like mentioned above. If the coach is used could it have been removed? Just a thought!!
It should be pretty easy to locate..and yes the plugs should have 110 while boondocking if the inverter is working.

[Chuck v]

Schooner,


As Bike Dr notes, the inverter could be turned off -- but even if it is working not ALL 110 volt outlets would necessarily be powered. In my coach the inverter powered designated loads/outlets but not all. The washer and dryer for instance were not on the inverter distribution at all, as was the case for several of the 110 utility outlets around the coach.


The most definitive way to see what might be on the inverter when it is operating is to look for a 110 volt breaker sub-panel that it feeds -- on my coach this is under the residential refrigerator and included loads that needed to be kept 'hot' when off shore power. On my coach, these included the refrigerator, the microwave, the front TV and a couple of convenience outlets.


The way the coach wiring is usually done is the shore power comes into the coach and passes through the transfer switch to all the 110 loads, either directly or indirectly. When there is no shore power, the generator feeds the other input to the transfer switch and gives its power to all the same 110 loads. However a portion of the loads further are routed through the internal transfer switch inside the inverter, which allows it to power SOME of the 110 loads even when the generator is not running. For my coach, having power to the residential refrigerator from the inverter allowed it to stay cool during a long drive. Your coach may have a refrigerator that also runs on gas, but the large (23 cu ft) unit in my rig only runs on 110 volt household power.


Look for some information on what outlets in your particular model of coach would be [powered by the inverter if present. If you have a residential refrigerator, most likely you have an inverter... Smaller rigs with Norcold or Dometic gas refrigerators may not have an inverter, but things vary quite a bit from model to model.


The brochure I find on-line for your 2004 Atrium indicates it came with an 8 cu ft refrigerator, so it may indeed not have any inverter.


Chuck

[Bike Dr]

That's interesting Chuck! As all of my outlets function as usual in all cases. Shore power 30 or 50 amp, gen or inverter. That goes to show just how many different configurations the systems can be from one model to the next. I hope to hear if schooner locates it..

[Chuck v]

Thanks for the comments, Bike Dr,


It is true that there are many variations on how these RV coaches are configured for 120 volt AC distribution, etc. If your coach has only a few convenience outlets and no heavy loads like a residential refrigerator, then it is possible that the inverter in yours has no secondary transfer switch.



I am pretty sure that there are some shore power loads on your coach that don't get serviced by the inverter, however -- such as the air conditioners, the electric element of the water heater, any washer or dryer that may be fitted, etc. As I understand it your coach is not diesel powered, so there is probably not an engine heater fitted, but that load is also not going to be driven from an inverter.



Mostly the inverter on these coaches are set up for the entertainment electronics, the convenience outlets, and perhaps the microwave. Careful selection of which loads in this group are active at once keeps the inverter within its load limits...


There may be older coaches that do not have factory fitted inverters, as these inverters were relatively more expensive a few decades ago than they are now. I know that my 24 volt input inverter for my off-grid home that I built in 1976 was a big expense, as were the solar panels and the four big L16 batteries, and of course the 1800 RPM Onan generator and 24 volt high amperage charger.


Chuck

[Chuck v]

Bike Dr and those following this thread,


I found a good wiring diagram that represents what my 2007 Tour Master looked like after I upgraded the factory inverter to a true sine inverter by Magnum. I have annotated it to reflect this discussion...


Hopefully you can enlarge it enough for clear reading, if not get back to me and I can send it to you separately.


Chuck

[Rincon Schooner]

Thank you Chuck… your response is very informative. We just returned from a two-nighter at the beach… never gets old!….. We have achieved a routine that is very comfortable and works well with the portable battery I take to watch TV. An inverter would be nice… I have a total of 2 six-volt deep cycle batteries, with room for one more. Not totally sure why I need an inverter, and wondering how it would change our routine for the better….?

[Chuck v]

Schooner,


If you 'boondock' at the beach or other places without a full hook-up you may not be doing activities that need much 120 volt AC power...sounds like your battery powered TV is serving the needs for now. An inverter may give you more flexibility in how you use/enjoy your entertainment electronics, but I presume you have a refrigerator that runs on propane when needed.



The second TV in my coach originally was a 12 volt powered one so it would work without any shore or inverter power...but I replaced it with a full 4K HD one for the video performance improvement. But then again, I was full time in that coach and not just out for a weekend.


It is your machine and you get to decide what suits you best...


Chuck

[THenne1713]

Inverter requires multi batteries, which I assume you have, and MW would be dead when boondocking without GEN=ON, so unless you are running GEN to run MW, you have Inverter. Inverter usually VERY CLOSE to batteries, (to limit long runs of BIG cable); I would be looking in compartments each side of batteries, maybe even mounting to compartment ceiling? Otherwise, just crawl under and FOLLOW each coach battery big cable= 1 to GEN, 1 to engine and 1 to Inverter, 1 to FUSE PANEL? All probably in corrugated protectors? Good Luck

[Chuck v]

Another thing to check is the factory brochure for your exact year and model of coach, as it may show what was standard equipment regarding the inverter. It would not cover what might have been optional...


Here is an excerpt from the GS factory brochure for my 2007 Tour Master -- notice that it shows the inverter as a standard feature and identifies the 4 each 6-volt batteries in the bank that powers it. This is the "as shipped" configuration which was then updated at a later date to the pure sine wave Magnum inverter...


Chuck

[hossross]

1) How far away from the battery is your inverter Bike Dr
2) For those that had factory installed inverters, how do they isolate the inverter from shore power. Ie if both are turned on do they both feed the common wall outlets? This should never be done as the phase relationship is not going to be synched and equipment will be fried. I suspect based on the switches that Bike Dr mentioned, it was up to the user to manually turn on and off the inverter, 1 to save the batteries, and 2 to protect from dual source of shore power AC and inverted AC. Inverted AC is always sloppy and will cause some overheating of equipment, unless it has been updated to true sign wave and only if it really is true, on just on the label.
Also my opinion on the use of inverters, they are not generally made to power high amperage 110 V electrical equipment. Ie AC never, refridgerator maybe but if starting amps is more than 8 thats a lot of DC power.
Inverters are great for modern TVs and and stereo systems as they are very low AC amperage draw. Infact for the older coaches, just getting a 500 watt inverter as an addon piece will power many TVs and not require either shore power or running the generator. I don't know what amps a modern microwave draws, but is nice to have the quick heater without starting the generator. But for the formula if 110 V and 5amps then that is 550 watts. if powered from inverter 550 watts divided by12 V equals almost 48 amps with conversion losses, so that requires big, big wire from the battery to the inverter. So small things can be powered by almost any 12 V source, but something a mild as 5 ams needs special and dedicated wiring to power the inverter.
I once saw a person wanting to by a Harbor Freight 2000 Watt inverter to run their oxygen generator in the RV to save running the generator while driving and overnight. They had no one to hook up the wires to the stand alone inverter, and had no idea it couldn't be powered off any 12V cigarette lighter connection. It is possible, just understand that watts must equal watts, to get the convince we desire. Chuck eluded to this in his post.

[Chuck v]

Hossross,


All the factory installed inverters that i am aware of have INTERNAL transfer switches to ensure that the inverter's reconstructed AC power from battery storage is not connected across the line sourced AC (or generator sourced AC) at the same time. The transfer switch function is the same as that of the generator and is cascaded to it -- the logic is if shore power is present, the AC loads are powered from that, if no shore power and the generator can run, then it starts up and the AC loads are powered from there (or a portion of the loads if it is a smallish generator...) and finally if the shore power AND the generator power are unavailable, then at least some portion of the AC loads get power from the inverter.


Inverters, like generators come in various sizes...so it is not true to say that large AC loads cannot be sourced/powered from an inverter. Below is a picture of a 45 foot custom Prevost coach I helped specify for a demonstration vehicle for a company I once was working for as the VP of technology, and it had sufficient inverter power to run the two basement air conditioners and the third roof unit (that cooled the complex electronics in the video equipment) for up to 6 or 8 hours continuously without the rather large battery bank needing a recharge. My own Tour Master coach did not allow any air conditioner to run off its inverter...


Chuck

[hossross]

Thanks for the reply and providing more accurate and complete info. I was posting in the context of the older coaches and generally non diesel and what they may have to deal with, considering upto 2004/5 technology. Also some suggestions if they were thinking of adding an inverter.

Those with the nice diesel and tour master like coaches, are in their own grouping.
Hope you had fun ordering that Prevost, money solves many problems, I still am not a fan of inverting large electrical loads, even when it can be done, I assume the application you mentioned used a 24 V inverter which cuts the amps in half by definition over a 12V Nice that you and Bike Dr offer quick and knowledgeable replies

[Chuck v]

Hossross,


Adding an inverter to any coach of any year using today's available RV targeted units like the Magnum will give you an INTERNAL transfer switch so you can have safe and convenient back-up 110 volt power in appropriate wattage depending on the unit and the battery bank selected. While efficiencies have increased over the years (as have wave shape improvements with true sine wave units being common now...) the inverter made by Trace that I used on my off-grid home in 1976 is essentially equivalent to the function of modern inverters. Unless you are just trying to 'get by' with a small inexpensive stand alone inverter from Harbor Freight or something similar for a CPAP or other dedicated load, a real RV inverter is going to be simple to install and maintain and convenient to use.


Yes the high wattage units were typically 24 or 48 volt designs, and the really big one I worked on for a solar company that made 7 tons of ice a day in the upper Egyptian desert ran on an input of 240 VDC and more current than you would be comfortable with. The batteries were enough to completely fill up a 40 foot cargo container and each cell was about waist high.


The large coach pictured had a turbo diesel generator to run the battery charger for its 24 volt banks (plural) and two 4 KW inverters. That project was in the early 2000 time frame. Some gas class A coaches had inverters in this same period, but more common to see them in the last 10 years or so.


There are lots of good articles on-line about adding an inverter to an existing RV, so a search should give you lots of information.


Chuck

[Bike Dr]

Okay sorry it took so long to get back to you as I have to work, but my inverter is about 12 to 15' from the batteries. The batteries are on the right side all the way to the rear behind the main chassis and coach switch compartment, the in verter is on the left side behind the rear wheel. I will try to post some pictures of where they are on my 05 8410 se.. your inverter/charger may look like this! Mine is a xantrex

[Chuck v]

Bike Dr,


That is the same Xantrex model that my coach came with, but it was mounted up front in the first bay on the driver's side in front of the front wheel. It ran on the 4 each 6 volt golf cart size batteries that were mounted up under the windshield just ahead of the diesel generator. The Xantrex charger feature only was applied to the 4 cart batteries (which also provided cranking to the diesel generator) and a separate 80 amp converter under the bed was used to charge the house batteries...


Gulf Stream used lots of configurations over the years and models...


By the way, I am always amazed by the rear axle overhang of the gas coaches...does yours bottom out on driveways at times? My diesel pusher had a 288 inch wheelbase and still had enough rear overhang to cause concern.



Chuck

[Bike Dr]

My atrium is a deisel pusher with a 350 hp turbo C7 cat with an Allison trans! I'd much rather have a deisel then a gas coach but that is just me. But no I do not drag or scrape once the air suspension is raised, it's very quiet with more then enough power even when towing my 20' inclosed trailer with a small car and motorcycle inside, this has been the perfect coach for us!